2 Answers

Karma on this site is points you earn for asking and answering questions. The members will give you a thumbs up if they choose to. It is suppose to reflect the level of trust the community has in your ability to give correct or helpful answers. It does not work that way however. For the most part, people just thumbs up the people they like. It's a broken system but the owners of the site like it.

Karma: the most simple explanation is "what you sow you will reap'  meaning that all acts of goodness you do will be rewarded in kind sometime. If you are a really lousy, selfish bad person then eventually all your acts of 'badness'  will catch up with you!! sometime, somewhere eventually!!

The idea of Karma originated in India.. in a nutshell people who have good karma are empathetic and sympathetic but it does not mean they are weak and that others take advantage of them!!